{"type_number":"5Z3","canonical_url":"https://tubeofile.com/tubes/5Z3","manufacturer":null,"tube_type_key":"rectifier","tube_type_display_name":"Rectifier","base_name":"UX4","description":"Full-wave high-vacuum rectifier with directly heated (filament) cathode. Uses a 4-pin UX4 base. Designed for high-current power supply applications in AC-operated receivers. Ratings and electrical characteristics are identical to the octal 5U4G and 5X4G — the 5Z3 is essentially the 4-pin predecessor to the 5U4G.","is_directly_heated":true,"completeness":"high","notes":["Directly heated (filament cathode) — observe heater warm-up time before applying B+ to protect the tube and filter capacitors.","Voltage drop of 58 V at 225 mA DC per plate.","With capacitor-input filter: max 450 V RMS per plate, 225 mA DC output, 75 Ω total effective plate supply impedance per plate.","With choke-input filter: max 550 V RMS per plate, 225 mA DC output, min 3 H input choke.","When filter condensers larger than 40 µF are used, it may be necessary to add additional plate supply impedance.","The 5Z3 is the direct 4-pin predecessor to the octal 5U4G — electrically identical. Replaced by 5U4G when the industry moved to octal bases."],"references":["https://frank.pocnet.net/sheets/127/5/5Z3.pdf"],"source_urls":{"r_type":null,"tdsl":"http://tdsl.duncanamps.com/show.php?des=5Z3","radiomuseum":"https://www.radiomuseum.org/tubes/tube_5z3.html"},"raw_equivalents":["CV1861","VT-145"],"equivalents":[],"similar":[{"type_number":"5U4G","reason":"Octal-based equivalent with identical ratings and characteristics — not pin-for-pin compatible due to different base (UX4 vs Octal)","has_detail_page":true},{"type_number":"5X4G","reason":"Octal-based equivalent with identical ratings — different base type and pinout","has_detail_page":false},{"type_number":"80","reason":"Same UX4 base but lower current rating (125 mA vs 225 mA) and lower filament current (2.0 A vs 3.0 A)","has_detail_page":true},{"type_number":"83","reason":"Same UX4 base, mercury-vapour rectifier — much lower voltage drop (15 V vs 58 V) but requires controlled warm-up and has limited life","has_detail_page":true}],"pins":[{"pin_number":"1","function":"Anode 1 (Plate 1)","function_code":"a1","notes":null},{"pin_number":"2","function":"Filament","function_code":"h","notes":null},{"pin_number":"3","function":"Anode 2 (Plate 2)","function_code":"a2","notes":null},{"pin_number":"4","function":"Filament","function_code":"h","notes":null}],"specs":[{"key":"Vh","display_name":"Heater Voltage","value":"5.0","numeric_value":"5","unit":"V","param_group":"heater"},{"key":"Ah","display_name":"Heater Current","value":"3.0","numeric_value":"3","unit":"A","param_group":"heater"}],"sections":[{"section_number":1,"section_label":"Rectifier","tube_type_key":"rectifier","specs":[{"key":"Va_max","display_name":"Anode Voltage (max)","value":"550","numeric_value":"550","unit":"V","param_group":"absolute_max"},{"key":"PIV","display_name":"Peak Inverse Voltage","value":"1550","numeric_value":"1550","unit":"V","param_group":"rectifier"},{"key":"Vdrop","display_name":"Voltage Drop (typical)","value":"58","numeric_value":"58","unit":"V","param_group":"rectifier"},{"key":"C_max","display_name":"Max C-input Filter Capacitor","value":"40","numeric_value":"40","unit":"µF","param_group":"rectifier"},{"key":"Ia_peak","display_name":"Peak Anode Current (surge)","value":"675","numeric_value":"675","unit":"mA","param_group":"rectifier"},{"key":"Idc_max","display_name":"Max DC Output Current (total, not per-anode)","value":"225","numeric_value":"225","unit":"mA","param_group":"rectifier"},{"key":"Rs_min","display_name":"Min Series Resistance (C-input)","value":"75","numeric_value":"75","unit":"Ω","param_group":"rectifier"}]}],"synced_at":"2026-04-08T07:51:12.299Z"}